BRUSSELS, Belgium (CNN) -- NATO officials cast doubt on
Yugoslavia's show of a withdrawal from Kosovo on Thursday,
telling reporters that Yugoslav troops there have died in "an
exercise in futility."

Diplomatic efforts continued Thursday as well: Russian
President Boris Yeltsin, beset by impeachment proceedings in
parliament, warned that his country might abandon peace
efforts if NATO continues to ignore its pleas to stop the
bombing.

A contingent of Yugoslav troops -- about 150 men -- left
Kosovo on Thursday, just days after the Yugoslav army
announced a withdrawal of half its forces from the Serb
province. But Maj. Gen. Walter Jertz, NATO's military
spokesman, said the alliance did not believe the movement
meant a large number of troops were pulling out.

"However, we strongly believe that effectiveness of our
recent air strikes against ground forces in Kosovo has caused
some tactical redeployment in the forward areas, probably to
seek better refuge or to regroup," he said.

NATO officials estimated there were about 40,000 Yugoslav
forces in Kosovo, including some 300 armored vehicles, when
the war began March 24.

Yugoslav PresidentSlobodan Milosevic conceded Wednesday that
"many" soldiers and special police have been killed during
NATO's attacks.

NATO spokesman Jamie Shea said those deaths could have been
avoided if Milosevic had agreed to a pact to end the ethnic
strife in Kosovo before the NATO bombing campaign began.

"Their bravery and sacrifice were more an exercise in
futility than in loyalty and patriotism," he said.

Shea said the partial withdrawal, even if genuine, is not
good enough for the allies.

"The only thing that makes sense is a full withdrawal, and
that's the only thing we're interested in," he said.

Shea said allied attacks at airfields in Batajnica and Obvra
destroyed five Yugoslav aircraft on the ground. He said
military communications sites at Kosovska, Novi Sad and Stara
Pazova also were hit, and Serbian television reported its
transmitter in Novi Sad was hit by NATO missiles.

Serbian television said NATO attacked sites in the
southeastern Serb town of Leskovac and Pirot, in eastern
Serbia. Serb TV also reported attacks on Pancevo, near
Belgrade; Pozarevac, Milosevic's birthplace; and the town of
Sabac.

Yugoslav state radio reported that Novi Sad's oil refinery
was bombed once again, and several towns in Kosovo were
bombed Thursday, including Srbac; a border area between
Decani and Djakovica; and Prizren, where bombs exploded near
a railway station and a hotel.

NATO has avoided strikes on the Yugoslav capital Belgrade for
nearly a week, since the accidental bombing of the Chinese
Embassy there killed three people early Saturday. But Shea
said that attack -- which NATO blamed on outdated maps -- did
not prompt allied air staffs to change their target list.

If NATO is avoiding Belgrade, he said, it's because the
alliance has shifted its priorities toward the Yugoslav army
in Kosovo, he said.

"If you have already destroyed or severely damaged the
Ministry of Defense or (special police) headquarters in
Belgrade, you don't have to hit it again," Shea said.

U.N. Human Rights Commissioner Mary Robinson left the
Yugoslav capital on Thursday after a trip to gauge the impact
of the war in Yugoslavia.

While recognizing suffering on both sides, Robinson leveled
the harshest criticism against Milosevic and his policies in
Kosovo, which she described as a campaign against ethnic
Albanian civilians.

"It is a devastating pattern of ethnic cleansing. The
suffering of the Kosovar Albanians is terrible and direct and
cruel," she said. "And the suffering of the civilian
population in this country is also very real and very cruel."

Yugoslav officials told Robinson more than 1,200 people have
been killed and 5,000 hurt during the fighting. Milosevic
did not meet with her despite repeated requests.

French President Jacques Chirac met with Yeltsin on Thursday
in Moscow for talks, during which he supported Moscow's
efforts to mediate between Belgrade and the West to help
resolve the Kosovo crisis.

After meeting with Chirac, Yeltsin reiterated earlier
warnings that Russia may halt its diplomatic efforts unless
it starts seeing some results.

The Russian president told Chirac that Russia "will have to
revise its participation in the negotiating process if NATO
continues bombing Yugoslavia despite Russia's active efforts,
and if Russian proposals are ignored," the Interfax news
agency reported.

Chirac played down such a risk. "We do not at all think that
Russia is ready to withdraw from a process which demands
its active presence," he said.

Meanwhile, Russian envoy Viktor Chernomyrdin assured U.S.
officials Wednesday that if Moscow and Washington reach a
peace proposal on Kosovo, China will not veto the plan in the
U.N. Security Council.

Chernomyrdin relayed the message to U.S. Deputy Secretary of
State Strobe Talbott, who was in Moscow.

U.S. officials said Chernomyrdin -- just back from Beijing --
told Talbott that Chinese leaders were enraged over the
bombing of the Chinese Embassy in Belgrade. But, the U.S.
sources say, Chernomyrdin also said the Chinese made clear
they "would not get in the way" if NATO and the Russians were
in agreement on a peace plan.

China has publicly threatened to hold up the proposal if it
were submitted to the Security Council, and called for NATO
to halt the bombing.

U.S. officials said they were encouraged by Chernomyrdin's
report. They also said Chernomyrdin told Talbott he plans to
head to Belgrade soon on another diplomatic mission.